Investigation of transient structures of photo-induced chemical reactions in solution with ultrafast XUV-photoelectron spectroscopy

在本项目中，利用我们最近开发的激光驱动液体、气体和聚合物喷射等离子体源，将产生1-4 nm(和13 nm)范围的超短XUV辐射。在超快泵浦和探测实验中，我们将用超快XUV-光电子能谱研究溶液中光诱导化学反应的暂态结构。在这项研究中，我们使用了含有溶质分子的真空中的稀薄液体喷射(5-8微米)的溶剂。对于足够高的能量辐射(EHV 400 EV)，1s的核心电子可以从液束界面附近的液体相中射出，用靠近溶剂束的撇油器收集，并用电子能谱仪进行分析。它们的动能提供了关于被研究分子中(C-，O-，N-)原子的化学环境(分子内和分子间)的信息。将时间分辨ESCA(电子光谱化学分析)技术应用于溶液中有机分子的动力学研究，结合高水平量子化学，将使我们能够明确地表征光诱导化学反应的瞬时结构、过渡态和微观机制，这反过来又允许我们理解所研究的体系的结构和反应性之间的关系。

In the present project ultrashort XUV radiation in the range 1-4 nm (and 13 nm) will be generated employing our recently developed laser driven liquid gas and polymer jet plasma sources. In ultrafast pump and probe experiments transient structures of photo induced chemical reactions in solution will be investigated by ultrafast XUV-photoelectron spectroscopy. For this investigation we use a thin liquid jet (5-8 µm) of the solvent in vacuum containing the solute molecules. For sufficiently high energy radiation (Ehv 400 eV) 1s core electrons can be ejected from the liquid phase near the interface region of the liquid beam, collected with a skimmer close to the solvent beam, and analyzed with an electron spectrometer. Their kinetic energy provides information about the chemical environment (intramolecular and intermolecular) of the (C-, O-, N-) atoms in the molecules under investigation. The time resolved ESCA technique (electron spectroscopy for chemical analysis) applied to the dynamics of organic molecules in solution in combination with high level quantum chemistry will enable us to unambiguously characterize transient structures, transition states, and microscopic mechanisms of photo induced chemical reactions which in turn allows for an understanding of the relationship between structure and reactivity of the systems investigated.